The present invention relates to a heat-insulating container made of paper, which is used for an instant dried food to be become eatable by pouring boiled water over it and an apparatus suitable for producing at least one part of the container.
As a heat-insulating container made paper mainly used for instant dried Chinese noodles, there has widely been used a container in which a paper cup body surrounded over its outer periphery with a heat-insulating corrugated member subjected to a process so as to make an alternate arrangement of narrow projections and recesses in the longitudinal direction of the cup body.
In Japanese Patent Provisional Publication No. H8-113274, there is proposed a heat-insulating container in which a change in its cross-sectional shape is made so that the total area of concave portions on the outer surfaces of the container is decreased and the total area of flat portions thereon is increased. Such a container has been put to practical use.
In Japanese Patent Provisional Publication No. H4-45216 and Japanese Patent Provisional Publication No. H8-104372, there is proposed a heat-insulating container, in which a heat-insulating member subjected to a corrugating process or an embossing process so that no irregularity is formed on the outer surface of the container.
In Japanese Utility Model Provisional Publication No. 4-45212, there is made, on the other hand, a proposal that a heat-insulating property is given by a gap formed between a double-walled cup body.
The above-described container having the cup body surrounded with the heat-insulating corrugated member has a problem that the container has an unnecessarily larger thickness even in the upper portion thereof, which is not brought into contact with a hand, regardless of the cross-sectional shape of the heat-insulating member. The irregularity on the outer surface of the container may become obstacle to a high grade design to be given to the container, and characters, patterns and the like printed on the surface thereof may be made unclear and vague, thus causing problems.
In order to solve such problems of the external appearance of the container, there is made a proposal to cause the above-mentioned container to be surrounded with an additional liner or thin sheet of paper in Japanese Utility Model Provisional Publication No. S49-87479 and Japanese Utility Model Publication No. H4-45216. The container obtained in accordance with such a proposal has an uneconomic problem that the high production cost is required, an external appearance problem that the heat-insulating container may has the irregular bottom and the narrow projections and recesses or the embossed portions may be visible from the bottom, and an unhygienic problem that dust or a liquid may enter gaps of these portions.
FIG. 43 is a cross-sectional view of a conventional heat-insulating container 50 proposed in Japanese Utility Model Provisional Publication No. H4-45212. The heat-insulating container 50 is obtained by inserting a paper cup body 51 composed of a bottom plate 52 and a side wall 3b3 having an outward curled top portion 54 into a sleeve 55 provided on its lower end with an inward curled portion 56, and integrally combining the cup body 51 and the sleeve 55 with each other at the upper and lower contact portions of them. A heat-insulating space is formed with the utilization of the thickness of the curled portion 56 of the sleeve 55.
Such a heat-insulating container 50 does not use any specific heat-insulating member and has therefore no disadvantage caused by the heat-insulating member. When the container is actually held at the central portion of the side wall thereof with a hand, the sleeve 55 may however easily be warped inward to decrease the capacity of the heat-insulating space, thus deteriorating the heat-insulating property.
In addition, a container in which a sleeve is disposed on an outer periphery of a cup body is also proposed, for example, in Japanese Utility Model Provisional Publication No. S52-97282, and Japanese Patent Provisional Publication No. H4-201840. The container disclosed in these publications is provided with an outward projecting rib and the sleeve bonded to the rib.
However, in such structure, since the rib is formed into a round or triangular shape in its cross-section, only a ridge portion of the rib contacts the sleeve, so that a bonding area between the rib and the sleeve reduces, causing the lack of the bonding strength. Since the position of the rib changes variously in accordance with the type of the container, it is necessary to adjust the position to which the adhesive agent is applied in accordance with the position of the rib, so that a preparation for the process may be troublesome. In particular, if the rib functions as the Peter line indicating proper level of liquid poured in the container, the position of the rib often changes in accordance with a kind of a product packaged in the container, and thus the above mentioned problem may be more serious. Also, if the Peter line is adjacent to the curled portion of the cup body, distance between the sleeve and the cup body reduces and the resistance force during the combination process may increase to thereby cause an assembling error.
Further, it is desired to provide an apparatus capable of producing the container efficiently. In particular, it is preferable to form the sleeve completely without changing a mandrel on which a sheet-like blank as a material of the sleeve is curled. It is also desired to assemble the sleeve and the cup body correctly and efficiently.
Furthermore, it is particularly desired to provide an apparatus capable of facilitate a process for forming the rib on the side wall of the cup body. In Japanese Patent Provisional Publication No. H4-97833, there is disclosed a rib-processing apparatus in which an expandable chuck is inserted into the cup body, and the chuck expands outward at a predetermined position in the cup body to enlarge the container outside, thereby forming the rib.
However, since the apparatus disclosed in the above publication forms the rib on the side wall of the cup body all at once over an entire periphery thereof, it is necessary to add a relatively great force to the side wall with using force-magnification means, such as a wedge or the like, even if the rib is relatively small. Therefore, it is difficult to form a large rib. Also, since the chuck is driven in the cup body, it is necessary to locate one part of a driving mechanism for the chuck in a narrow space in the cup body, so that structure of the mechanism becomes complex. It needs a long time to take the chuck in and out against the cup body, so that it is difficult to form the rib efficiently.
One of objects of the present invention, which was made in order to solve the above-mentioned problems, is to provide a heat-insulating container made of paper, which has a stable heat-insulating property, a high grade design, a high degree of freedom in indication by printing on the outer surface of the container, and a lower production cost.
In order to attain the above-described object, the heat-insulating container of the present invention comprises:
a paper cup body with a bottom, which has an inner surface coated with a polyolefin resin and is provided with an outward curled portion formed at an upper opening end of the cup body and at least one horizontal rib formed on a side wall of the cup body so as to project outward therefrom; and
an inverse-frustoconical paper sleeve provided with an inward curled portion formed at a lower end of the sleeve,
the cup body and the sleeve are integrally combined with each other so that an upper end of the sleeve is joined to an outer periphery of the side wall of the cup body, which is adjacent to the outward curled portion of the cup body, and an inner surface of the inward curled portion of the sleeve is joined to an outer periphery of a lower portion of the side wall of the cup body.
Any number of the horizontal rib may be formed so as to extend continuously over the entire periphery or intermittently in the circumferential direction of the side wall of the cup body.
A heat-insulating corrugated member may be arranged between the sleeve and the upper portion of the side wall of the cup body.
According to the above invention, it is possible to provide the heat-insulating container made of paper, which is excellent in design and has a stable heat-insulating property, a smooth outer surface, a high grade external appearance and a high degree of freedom in indication by printing.
The container has an appropriate rigidity so as to prevent the occurrence of warp of the side wall, and it can therefore be easily held with a hand, with the result that it is possible to improve safety required for the container, which is to be filled with boiled water to make an instant dried food eatable received therein.
In addition, it is possible to prevent costs for material and production from rising, thus permitting the provision of the heat-insulating container at a low cost.
The heat-insulating container of the present invention is made of paper so as to be disposed easily without being subjected to segregated disposal, and it is also easy to decrease the volume of the container in the light of disposal thereof, thus leading to an excellent disposability. The container can easily be recycled. Thus, the present invention contributes to decrease in adverse influence on environment.
Another object of the present invention is to provide a heat-insulating container having improved structure in which a sleeve is surely bonded to a cup body.
In order to attain the above-mentioned object, there is provided a heat-insulating container comprising:
a cup body having a side wall and a bottom disposed on one end of the side wall, the side wall being provided with an outward projecting rib extending in a circumferential direction thereof and being provided at another end thereof with an outward curled portion; and
a sleeve disposed outside the side wall with leaving a space therebetween and bonded to the side wall in a bonding area defined so as to be adjacent to the outward curled portion of the cup body,
wherein the outward projecting rib is disposed only on an area apart from the bonding area.
According to the above container, since the outward projecting rib is eliminated from the bonding area, the sleeve and the side wall of the cup body can widely contact each other, so that the size of the bonding area is increase to thereby improve the bonding strength between the sleeve and the cup body. The bonding area is always disposed adjacently to the outward curled portion formed on a periphery of the opening end portion of the cup body, so that the position to be applied with the adhesive agent is not changed, regardless of the position of the outward projecting rib.
The sleeve may be provided at one end thereof with an inward curled portion capable of contacting an outer periphery of the one end of the side wall.
The side wall of the cup body may be provided with an inward projecting rib extending in the circumferential direction thereof. The inward projecting rib can be included in the bonding area, to thereby improve rigidity of the cup body without reducing the bonding are. The inward projecting rib may function as a line indicating a proper level of liquid poured into the cup body. The rib as the Peter line may be provided in the bonding area so as to be close to the outward curled portion.
According to still another aspect of the present invention, there is provided a heat-insulating container comprising:
a cup body having a side wall and a bottom disposed on one end of the side wall; and
a sleeve disposed outside the side wall with leaving a space therebetween and bonded to the side wall;
wherein a rib indicating a proper level of liquid poured into the cup body is provided on the side wall so as to project inward therefrom.
In this case, it is possible to keep the bonding area sufficiently by defining it so as to include the rib as the Peter line.
According to still another aspect of the present invention, there is provided a heat-insulating container comprising:
a cup body having a side wall and a bottom disposed on one end of the side wall, the side wall being provided at another end thereof with an outward curled portion; and
a sleeve disposed outside the side wall with leaving a space therebetween and bonded to the side wall in a bonding area defined so as to be adjacent to the outward curled portion of the cup body;
wherein the side wall is provided with an inward projecting rib included in the bonding area.
In this case, it is possible to keep the bonding area sufficiently by defining it so as to beyond the inward projecting rib toward the bottom of the cup body.
Still another object of the present invention is to provide a producing apparatus which can produce a heat-insulating container efficiently and rationally.
In order to attain the above-mentioned object, there is provided a producing apparatus for combining a sleeve on an outer periphery of a cup body to produce a heat-insulating container comprising:
a sleeve forming section for forming the sleeve by curling a blank sheet cylindrically and joining both ends thereof; and
an assembling section for combining the sleeve on the outer periphery of the cup body;
the assembling section comprises;
a rib-processing device for processing a rib on a side wall of the container;
an adhesive-applying device for applying an adhesive agent on the side wall of the cup body formed with the rib; and
a sleeve-delivering device for putting the sleeve formed by the sleeve forming section on the outer periphery of the cup body on which the adhesive agent is applied.
According to the above producing apparatus, the rib is formed on the cup body and the adhesive agent is applied thereto in the assembling section, while the sleeve is formed from the blank in the sleeve forming section. Then, the formed sleeve is put on the outer periphery of the cup body applied with the adhesive agent to combine them together. Since the processes necessary for producing the container are simultaneously with each other in two sections, it is possible to produce the container efficiently and rationally.
According to still another aspect of the present invention, there is provided a producing apparatus for combining a sleeve on an outer periphery of a cup body to produce a heat-insulating container comprising:
a sleeve holder capable of holding the sleeve;
a cup holder capable of holding the cup body; and
a driving device for circulating the sleeve holder and the cup holder along respective certain circulation paths,
wherein the apparatus is provided along the circulation path of the sleeve holder with a curling device for curling up a sheet-like blank on the sleeve holder and for joining both ends of the curled blank to each other and a sleeve-ejecting device for removing the sleeve from the sleeve holder;
the apparatus is also provided along the circulation path of the cup holder with a cup-body-supplying device for supplying the cup body to the cup holder, a rib-processing device for processing a rib on a side wall of the cup body set on the cup holder, an adhesive-applying device for applying an adhesive agent to the side wall of the cup body formed with the rib, and a sleeve-delivering device for receiving the sleeve ejected by the sleeve-ejecting device and for putting the received sleeve on the outer periphery of the cup body on which the adhesive agent is applied; and
the driving device drives the sleeve holder and the cup holder in such a manner that the cup body on which the adhesive agent is applied is carried in the sleeve-delivering device when the sleeve on the sleeve holder is carried in the sleeve-ejecting device.
In this apparatus, the blank is curled on the sleeve holder to form the sleeve, and the prepared sleeve is removed from the sleeve holder and ejected to the sleeve-delivering device in accordance with the circulation of the sleeve holder. On the other hand, the cup body is set on the cup holder and carried in the sleeve-delivering device, after the rib is processed on the cup body and the adhesive agent is applied thereon. Then, the formed sleeve is put on the outer periphery of the cup body applied with the adhesive agent to combine them together. Since the processes necessary for producing the container are simultaneously with each other in two sections, it is possible to produce the container efficiently and rationally.
A end-curling device for processing a curled portion on one end of the sleeve may be provided on the circulation path of the sleeve holder.
A sleeve-fitting device for pressing the sleeve which is put on the cup body by the sleeve-delivering device toward the cup body with aligning the sleeve with respect to the cup body may be provided on the circulation path of the cup holder.
The apparatus may further comprise a blank-supplying device for supplying the blank to the curling device, and the blank-supplying device may be provided with an adhesive applicator for applying an adhesive agent to one end of the blank.
A sealing device for pressing both ends of the blank overlapped by the curling device to each other may be provided on the circulation path of the sleeve holder. The sealing device may be provided with a heater therein to hasten the adhesion between the cup body and the sleeve.
Still another object of the present invention is to provide a sleeve forming apparatus which can form a sleeve of a heat-insulating container efficiently, especially can perform an operation for curling up a blank on a mandrel and an operation for processing an end-curled portion to the curled blank without changing the mandrel.
In order to attaint the above object, there is provided a sleeve forming apparatus for forming a sheet-like blank into a sleeve used as an outer package of a heat-insulating container, comprising:
a mandrel having a body portion which is capable of being fitted inside the sleeve and which is shorter than the sleeve;
a curling device for curling up a blank on the mandrel in such a manner that one end portion of the blank to which an adhesive agent is applied is located under another end portion of the blank to form a joint line;
a main-sealing device for pressing the joint line onto the mandrel;
an assist-sealing device for nipping one end portion of the joint line, which projects from the mandrel by a pair of nippers;
an end-curling device for pressing a projecting portion of the blank, which projects from the mandrel, toward the mandrel to form a curled portion of the sleeve; and
a sleeve-ejecting device for removing the sleeve from the mandrel.
According to the above sleeve forming apparatus, since one part of the blank curled on the mandrel projects therefrom, it is possible to form a curled portion of the sleeve with the sleeve being mounted on the mandrel. The end portion of the joint line can be pressed by the assist-sealing device, and the joint line is thus joined certainly.
The sleeve forming apparatus may further comprise a blank-supplying device for supplying the blank to the curling device with applying the adhesive agent to the one end of the blank.
The sleeve forming apparatus may further comprise: a conveyor capable of circulating along a predetermined circulation path and having mandrel-attachment portions arranged along the circulation path with leaving a certain interval therebetween, each of the attachment portions being provided with the mandrel; and a driving device for moving the conveyor intermittently by a pitch corresponding to the interval between the mandrel-attachment portions to feed the mandrel on each of the mandrel-attachment portions step by step with respect to a plurality of stations defined along the circulation path; and the curling device, the assist-sealing device, the end-curling device and the sleeve-ejecting device may be distributed to the stations in such a manner that the mandrel is fed to the curling device, the assist-sealing device, the end-curling device and the sleeve-ejecting in this described order in accordance with movements of the conveyor.
The main-sealing device may be movable along the circulation path together with the mandrel.
According to still another aspect of the present invention, there is provided a sleeve forming apparatus for forming a sheet-like blank into a sleeve used as an outer package of a heat-insulating container, comprising:
a conveyor capable of circulating along a predetermined circulation path;
a plurality of mandrels arranged on the conveyor so as to leave a certain interval therebetween in a circulation direction of the conveyor;
a driving device for moving the conveyor intermittently by a pitch corresponding to the interval between the mandrels to feed each of the mandrel step by step with respect to stations defined along the circulation path;
a blank-supplying device for supplying the blank to a curling station selected from the stations with applying an adhesive agent to one end portion of the blank;
a curling device for curling up the supplied blank on each of the mandrels in such a manner that said one end portion of the blank is located under another end portion thereof to form a joint line;
a sealing device for pressing both end portions of the blank, which forms the joint line, to each other; and
a sleeve-ejecting device provided in an ejecting station which is selected from the stations and is located forward from the curling station in the circulation direction for removing the sleeve from each of the mandrels.
According to this sleeve forming apparatus, every time the conveyor moves by a certain amount, one mandrel holding the prepared sleeve is carried in the sleeve-ejecting device. The operation of the curling device and the operation of the sleeve-ejecting device are performed simultaneously with each other, so that the sleeve is formed efficiently.
Each of the mandrels may have a body portion which is capable of being fitted inside the sleeve and which is shorter than the sleeve, and the sealing device may comprise a main-sealing device for pressing the joint line of the blank to each of the mandrels and an assist-sealing device for nipping one end portion of the joint line, which projects from each of the mandrels, by a pair of nippers.
The assist-sealing device may be provided in an assist-sealing station selected from the stations and located between the curling station and the ejecting station.
The assist-sealing device may be provided in an assist-sealing station selected from the stations and located between the curling station and the ejecting station.
An end-curling device for processing an curled portion on a projecting portion of the blank, which projects from each of the mandrels, may be provided in at least one end-curling station selected from the stations and located between the assist-sealing station and the ejecting station.
The stations may include at least two end-curling stations, each of which is provided with the end-curling device.
The sleeve-ejecting device may remove the sleeve from each of the mandrels by pressing a roller onto the sleeve fitted on each mandrel with rotating the roller about an axis perpendicular to an axis of each mandrel.
The conveyor may comprise a turn table capable of turning about a predetermined axis.
Still another object of the present invention is to provide an assembling apparatus which can combine a sleeve and a cup body efficiently and correctly.
In order to attain the above-mentioned object, there is provided an assembling apparatus for combining a sleeve on an outer periphery of a cup body to produce a heat-insulating container, comprising:
a conveyor capable of circulating along a predetermined circulation path;
a cup holder mounted on the conveyor and having a rotary portion capable of rotating about an axis thereof with holding the cup body thereon;
a driving device for moving the conveyor to feed the cup body step by step with respect to stations defined along the circulation path;
a holder driving device provided in a driving station which is selected from the stations and capable of being connected with the rotary portion of the cup holder in the driving station to rotate the cup holder;
an adhesive-applying device provided in an applying station which is selected from the stations and is located forward from the driving station in a circulation direction of the conveyor and capable of applying an adhesive agent on an outer periphery of the cup body; and
a sleeve-delivering device provided in a delivering station which is selected from the stations and is located forward from the applying station in the circulation direction and capable of putting the sleeve on the cup body.
According to the above assembling apparatus, when the cup holder holding the cup body is carried in the holder driving device, the rotary portion of the cup holder is rotatably driven by the holder driving device. Therefore, it is possible to perform various processing, preferably processing of elements extending in the circumferential direction of the cup body, such as the rib, with using the rotation of the cup body. If the cup body is carried into the adhesive-applying device while the cup body keeps its rotation due to inertia thereof, it is possible to apply the adhesive agent on the outer periphery of the cup body without driving the cup holder. Therefore, it is not necessary to provide any driving means for rotating the cup holder in the adhesive-applying device. Also, it is not necessary to provide any driving means for rotating the cup holder on the conveyor. As a result, the structure of the assembling apparatus is simplified.
The rotary portion of the cup holder may be provided with a disk-like rotation input portion coaxial with the cup body, and the holder driving device may comprise a rotation output portion and a drive power source for rotating the rotation output portion.
The adhesive-applying device may be provided with a nozzle ejecting the adhesive agent toward the outer periphery of the cup body.
The cup holder may be provided with an abutment portion capable of being brought into contact with an inner surface of a side wall of the cup body, and the holder driving device may comprise a press mechanism capable of pressing a predetermined model member to the abutment portion with nipping the side wall therebetween to process the side wall.
The conveyor may comprise a turn table capable of turning about a predetermined axis.
According to another aspect of the present invention, there is provided an assembling apparatus for combining a sleeve on an outer periphery of a cup body to produce a heat-insulating container, comprising:
a cup holder capable of holding the cup holder in an inverted posture in a vertical direction;
a sleeve-delivering device capable of putting the sleeve on the outer periphery of the cup body held on the cup holder from the upper side thereof; and
a sleeve-fitting device having a jig capable of contacting an end portion of the sleeve put on the cup body in an axial direction thereof, the sleeve-fitting device being capable of pressing the jig toward the cup body to arrange the sleeve and the cup body with each other in an axial direction thereof;
wherein the jig is provided with an aligning equipment capable of engaging with the sleeve before the sleeve is pressed down by the jig to move the sleeve in a radial direction thereof so as to be aligned with the cup body.
According to the above assembling device, if the sleeve is put on the cup body in a miss-alignment manner, the sleeve is moved in its radial direction by the aligning equipment so as to be aligned against the cup body.
The aligning equipment may comprise pins arranged around the axis of the cup body on the cup holder.
Each of the pins may be supported by a jig body of the jig so as to be movable in the vertical direction, and a lower end portion of each of the pins may be formed with a tapered or rounded portion capable of contacting a lower end of a side wall of the cup body, which surrounds a bottom of the cup body.
Still another object of the present invention is to provide a rib-processing apparatus which can form a rib on a side wall of a cup body with reducing force to be added to the cup body and simplify structure thereof. Preferably, the rib-processing apparatus can form an outward projecting rib by an operation performed outside the cup body, and improve efficiency of process by omitting an operation of moving a model or the like in and out against the cup body.
In order to attain the above-mentioned object, there is provided a rib-processing apparatus for processing a rib on a side wall of a cup body so as to extend in a circumferential direction of the side wall comprising:
a male and a female model members disposed opposite to each other with putting the side wall therebetween, the male model member being provided on a portion facing the female model member with a projection to form a concave side of the rib, and the female model member being provided on a portion facing the male model member with a groove to form a convex side of the rib;
a radial direction driving device for moving at least one of the male and the female model members in a radial direction of the cup body so as to let the male and the female model members close to and away from each other;
a circumferential direction driving device for making a relative rotation between the cup body and at least one of the male and the female model members to change a position at which the side wall is nipped between the male and the female model members in the circumferential direction.
According to the above rib-processing apparatus, it is possible to form the rib gradually in the circumferential direction of the cup body, in accordance with the relative rotation between the cup body and the male or the female model member. Therefore, it is possible to reduce force added to the cup body during the process in comparison with the case in which the entire rib is formed at once.
The rib-processing apparatus may further comprise a cup holder capable of rotating about an axis thereof with supporting the cup body from an inside thereof, the cup holder may be provided with one of the male and the female model members, another one of the male and the female model members may be disposed on an outer periphery of the cup body, the radial direction driving device may move said another one of the male and the female model members in the radial direction of the cup body, and the circumferential direction driving device may rotate the cup holder.
One of the male and the female model members provided on the cup body may extend continuously over an entire periphery of the side wall of the cup body. In this case, it is possible to nip the side wall of the cup body by moving the male or the female model member provided outside the cup body in the radial direction, and under this condition, the rib can be formed by rotating the cup body. It is not necessary to drive the model member inside the cup body in the radial direction, and the model member outside the cup body may be driven only in the radial direction. Therefore, it is possible to simplify the structure of the apparatus.
A roller rotatable about an axis parallel to an axis of the cup body may be provided as said another one of the male and the female model members disposed on the outer periphery of the cup body.
The rib-processing apparatus may further comprise a restraining device for preventing the cup body from rising up from the cup holder.
The male model member may be provided inside the cup body, and the female model member may be provided outside the cup body.
According to still another aspect of the present invention, there is provided a rib-processing apparatus for processing a rib on a side wall of a cup body so as to extend in a circumferential direction of the side wall comprising:
a cup holder capable of rotating about an axis of the cup body with holding the cup body from an inside thereof;
a rotary drive mechanism for rotating the cup holder; and
a press mechanism which is provided on one side of the cup holder and which has a press roller rotatable about an axis parallel to the axis of the cup body and a driving power source for moving the press roller reciprocally in a radial direction of the cup body,
wherein one of a groove for forming a convex side of the rib and a projection for forming a concave side of the rib is provided on an outer periphery of the press roller, and another one of the groove and the projection is provided on the cup holder so as to accord a position thereof in a direction parallel to the axis of the cup holder with a position of said one of the groove and the projection provided on the press roller.
In this apparatus, the rib is formed on the side wall of the cup body gradually in the circumferential direction thereof by the steps of holding the cup body from the inside thereof by the cup holder, pressing the press roller on the side wall to nip the side wall between the groove of the press roller and the projection of the cup holder, and rotating the cup holder together with the cup body held thereon. Therefore, it is possible to reduce force added to the cup body during the process in comparison with the case in which the entire rib is formed at once. Since no member in the cup body is driven in the radial direction of the cup body and the press roller is only driven in the radial direction, it is possible to simplify the structure of the apparatus. Since the press roller can rotate about its axis, it is possible to reduce friction between the roller and the side wall of the cup body.
The rib-processing apparatus may further comprise a conveyor for conveying the cup holder through a plurality of processes, and the rotary driving mechanism and the press mechanism may be provided intermediate positions of a conveying path of the conveyor.
According to still another aspect of the present invention, there is provided a process for forming a rib on a side wall of a cup body so as to extend in a circumferential direction of the cup body, comprising by the steps of:
nipping one part of the side wall of the cup body by a male and a female model members, the male model member being provided on a portion facing the female model member with a projection to form a concave side of the rib, and the female model member being provided on a portion facing the male model member with a groove to form a convex side of the rib; and
making a relative rotation between the cup body and at least one of the male and the female model members to change a position, at which the side wall is nipped between the male and the female model members in the circumferential direction of the side wall.
In this process, the rib is formed on the side wall of the cup body gradually in the circumferential direction thereof in the same manner as is mentioned above. Therefore, it is possible to reduce force added to the cup body during the process in comparison with the case in which the entire rib is formed at once.
In the above process, the cup body may be held from an inside thereof by an cup holder capable of rotating about an axis of the cup body, the cup holder may be provided with one of the male and the female model members, another one of the male and the female model members may be pressed on a side wall from an outside thereof to nip the side wall between the male and the female model members, and under this condition, the cup holder may be rotated.
A bottom of the cup body may be pressed down to the cup holder when the side wall is nipped by the male and the female model members.